Interspinous process device versus conventional decompression for lumbar spinal stenosis: 5-year results of a randomized controlled trial

Journal of Neurosurgery Spine, vol. 36, pp. 909–917

Abstract

OBJECTIVE: Interspinous process distraction devices (IPDs) can be implanted to treat patients with intermittent neurogenic claudication (INC) due to lumbar spinal stenosis. Short-term results provided evidence that the outcomes of IPD implantation were comparable to those of decompressive surgery, although the reoperation rate was higher in patients who received an IPD. This study focuses on the long-term results. METHODS: Patients with INC and spinal stenosis at 1 or 2 levels randomly underwent either decompression or IPD implantation. Patients were blinded to the allocated treatment. The primary outcome was the Zurich Claudication Questionnaire (ZCQ) score at 5-year follow-up. Repeated measurement analysis was applied to compare outcomes over time. RESULTS: In total, 159 patients were included and randomly underwent treatment: 80 patients were randomly assigned to undergo IPD implantation, and 79 underwent spinal bony decompression. At 5 years, the success rates in terms of ZCQ score were similar (68% of patients who underwent IPD implantation had a successful recovery vs 56% of those who underwent bony decompression, p = 0.422). The reoperation rate at 2 years after surgery was substantial in the IPD group (29%), but no reoperations were performed thereafter. Long-term visual analog scale score for back pain was lower in the IPD group than the bony decompression group (p = 0.02). CONCLUSIONS: IPD implantation is a more expensive alternative to decompressive surgery for INC but has comparable functional outcome during follow-up. The risk of reoperation due to absence of recovery is substantial in the first 2 years after IPD implantation, but if surgery is successful this positive effect remains throughout long-term follow-up. The IPD group had less back pain during long-term follow-up, but the clinical relevance of this finding is debatable.

Authors 7

1. Catharina D. Schenck

   Medisch Centrum Haaglanden · Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Department of Neurosurgery and

   Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

   Department of Neurosurgery and; Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

2. Sietse E S Terpstra
   Affiliation as printed

   Department of Neurosurgery and

   1Department of Neurosurgery and

3. Wouter A. Moojen

   Medisch Centrum Haaglanden · Haga Hospital · Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Department of Neurosurgery and

   Department of Neurosurgery, HAGA Teaching Hospital, The Hague, The Netherlands; and

   Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

   Department of Neurosurgery and; Department of Neurosurgery, HAGA Teaching Hospital, The Hague, The Netherlands; and; Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

4. Erik W. van Zwet Aachen Department of Biostatistics, Leiden University Medical Center 2Department of Biostatistics

   Leiden University Medical Center

   Affiliation as printed

   Department of Biostatistics, Leiden University Medical Center, Leiden, The Netherlands;

   2Department of Biostatistics, Leiden University Medical Center, Leiden, The Netherlands

5. Wilco C. Peul

   Medisch Centrum Haaglanden · Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Department of Neurosurgery and

   Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

   Department of Neurosurgery and; Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

6. Mark P. Arts

   Medisch Centrum Haaglanden · Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

   3Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands

7. Carmen L. A. Vleggeert-Lankamp

   Medisch Centrum Haaglanden · Spaarne Ziekenhuis · Haga Hospital · Spaarne Gasthuis · Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Department of Neurosurgery and

   Department of Neurosurgery, HAGA Teaching Hospital, The Hague, The Netherlands; and

   Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;

   Department of Neurosurgery, Spaarne Hospital, Hoofddorp/Haarlem, The Netherlands

   Department of Neurosurgery and; Department of Neurosurgery, HAGA Teaching Hospital, The Hague, The Netherlands; and; Department of Neurosurgery, Haaglanden Medical Center, The Hague, The Netherlands;; Department of Neurosurgery, Spaarne Hospital, Hoofddorp/Haarlem, The Netherlands